DESCRIPTION (Taken from application) Large quantities of toxic metals remain dispersed in the environment where their distribution and fate are imperfectly characterized, especially near large urban centers where both emissions and population density are concentrated. Moreover, significant quantities of metals continue to be added to the environment, particularly to natural waters where they accumulate in sediments and, in cases such as Hg, can be accumulated by fish and thus reach human diets. A central aim of this project will be to better characterize current sources and transport mechanisms of Pb, Hg and other metals to the NY metropolitan area and Hudson River basin. We will continue to work in very close collaboration with ongoing research on chlorinated hydrocarbons. Our approach will be to reconstruct and extend temporal trends in contaminant levels, including Pb isotope compositions, through analysis of dated environmental samples (airborne particulate matter from filters, sediments core depth profiles and landfill ash deposits of known age) to assemble the history of development and use of municipal and non-municipal waste incinerators in New York City, and to compare our sediment-derived contaminant history to NYS DEC's database on contaminant levels in fish from several parts of the Hudson River basin. We will expand our use of urban lakes and park soils to characterize the temporal history and geographical extent of urban atmospheric deposition rates of metals. Data generated should allow us to investigate potential for human exposure to metals and chlorinated hydrocarbons from city parks and community gardens, to investigate human exposure pathways of chlorinated organics and Hg via fish consumption, and contribute to ongoing state and federal investigations of Superfund sites within the metropolitan area and Hudson River Basin.